If the installation was amazingly fast (instead of 25 minutes or so with lots of text scrolling on screen), then you probably got an error while copying files from the CD to the disc. To test for this, type "aptitude install pluto-dcerouter" at a prompt (Alt+F2, login as root). If it gives you a list of "Package pluto-dcerouter depends on packages xxx but it can't be installed" entries, then this is your case. Unfortunately there's no way to test if the disc is ok (actually, you can try do copy the entire disc to a temporary location under Windows - or your OS of choice - and see if you get any reading errors).
Also, try not to write discs at max speed. The burning time, from my experience, at 24x and 40x is very similar, so the extra "speed" is not worth it. I write all my discs at 24x and they don't cause problems to anyone, while the two discs I wrote at 40x do. For "safe writes" I use 16x. So the speeds I recommend as "tested" are 16x and 24x, but not more (less is ok).